1. Field of the Invention
This invention relates to a manifold for mounting a plurality of turbochargers within an efficient space density, so that the turbines are driven in parallel from engine exhaust gas flowing from a high pressure chamber within the manifold and the turbines discharge into a common low pressure chamber within the manifold. A baffle is positioned within the manifold to separate the high pressure chamber from the low pressure chamber, and to make efficient space density use of the manifold for mounting the multiple turbochargers.
2. Description of Prior Art
Lean combustion is a well known technique for reducing nitrogen oxides (NO.sub.x) for natural gas spark-ignited two-cycle engines. Recent environmental regulations require maximum allowable NO.sub.x emissions that are lower than the levels at which many existing natural gas combustion engines operate. It is known that such existing natural gas combustion engines can operate at the reduced NO.sub.x emission levels if the air/fuel ratio is increased to the lean limit by use of turbochargers to significantly increase the air flow to the engine. However, depending upon the particular existing unit and the desired NO.sub.x emissions and fuel consumption levels, the cost of hardware alone for a custom designed single turbocharger unit can range from $US 300,000 to over $US 1,000,000. In addition, costs for labor and auxiliary equipment required for installation of such custom hardware could even equal the hardware costs. Thus, there is an apparent need for an apparatus and method that can be used to retrofit existing natural gas combustion engines, at a much reduced cost than the cost associated with a custom designed single turbocharger.
U.S. Pat. No. 4,464,902 discloses an apparatus having multiple turbochargers with a common exhaust housing. Two turbines are connected together and mounted on central support brackets. A common turbine discharge housing deflects turbine exhaust toward an outlet funnel. Diffuser horns and hollow central plugs are used to establish static pressure and thus uniform gas flow pressure distribution throughout the outlet funnel. Each turbine is equipped with a separate turbine casing which handles independent inlet flow to the corresponding turbine.
U.S. Pat. No. 4,400,945 teaches multiple exhaust gas turbochargers. The turbines of the exhaust gas turbochargers and the exhaust gas conduits are located within an interior of at least one housing which is arranged on an internal combustion engine. The compressors of the exhaust gas turbochargers and the associated air conduits are located on the exterior of the housing or housings.
The prior art does not seem to teach an apparatus that can be used to mount multiple conventional or off-the-shelf turbocharger units within an efficient space density, for the purpose of operating the off-the-shelf turbochargers in parallel to accomplish flow similar to that of a custom designed single turbocharger unit.